Unsymmetkical indigoid dyesttjffs



Patented Oct. 19, 1937 UNITED? STATES .PATENT OFFICE "UNSYMM ETRICAL INDIGOID DYESTUFFS Rabat Stocker, Basel, and Jakob Muller, Munchenstein; near Basel, Switzerland, assignors'to Society of Chemical Industry Switzerland in Basle, Basel,

lilo Application July 3, 1 936,.Serial No.

v p 88,894. In Switzerland July 10, 1935 3 Claims. (01. 260--53) V 7 tint is obtained when the dyestufi is used for This invention relates to the manufacture of unsymmetrical indigoid vat-dyestuffs by condensing an 8-halogen-1:2-(3'-hydroxy-1-thiophene) -naphthene or a reactive 2-derivative thereof with a 2-derivative of a 2:1-(3'-hydroxy 1'thiophene)-.naphthene or with a 2:1(3'- hydroxy-1-thi0phene) -naphthene. As 2-derivatives of these (3'-hydroxy-1-thiophene)- naphthenes there may be used, for example, the

halides, anils, ketones, carboxylic acids or oxims. The condensation is best performed by heating the components together in' a solvent or diluent,

for instance in alcohol, glacial acetic acid, ben- I stulTs entailing the known disadvantages.

The following examples illustrate the inven tion, the parts being by weight:-

Example 1 234 parts of 8-ohloro-1:2-(3'-hydroxy-1'-thiophene) -naphthene and 332 parts of para-dimethylamino-2-anil of 2:1-(3'-hydroxy-1'- thiophene)-naphthene are together heated to boiling in 4000 parts of chlorobenzene for several hours. The dyestufi of the formula 01 S\ /CO which separates in good yield is filtered, washed and dried. It is a dark brown powder, soluble in sulfuric acid to a violet-blue solution. It forms a greenish-yellow vat and dyes cotton and artificial silk from regenerated cellulose powerful blackish-brown tints of excellent fastness to chlorine, washing and light. The same color blackish-brown tints.

printing, for example, artificial silk from ,reg en. erated cellulose or cotton.

A dyestuff having similar properties is obtained by using the para-dimethylamino-2'-anil 5 of such a 2:1-(3'-hydroxy-1ethiophene) -naphthene which still carries substituents in the naphthalene nucleus, such as, for example, halogen or alkoxy groups.

Example 2 366 parts of para-dimethylamino-2-anil of 8- chloro-l :2- (3' -hydroxy 1'-thijophene) -napthene and 332 parts of 2:1-(3-hydroxy-1-thiophene) naphthene are together heated to boiling in 4000 parts of chlorobenzene until the condensation to dyestuff is complete. The mixture is filtered and the separated dyestufi 'washed with chlorobenzene and alcohol and dried. It is identical with that obtained as described in Example 1.

Example 3 279 parts of S-bromo-l:2-(3-hydroxy-1'- thiophene) -naphthene and 332 parts of paradimethylamino-2'-anil of 2:1-'(3-hydroxy-1- thiophene) -naphthene are together heated to boiling in 4000 parts of chlorobenzene until condensation is complete. After filtration and drying, the dyestufi of the formula s 00 Br is a dark-brown powder soluble in concentrated sulfuric acid to a violet-blue solution and dyeing. cotton in a greenish-yellow vat fast, powerful The prints produced with the aid of this dyestufi are considerably blacker than those obtained by using the dyestuff of Examples 1 and 2. V

The 8-bromo-1 2- 3 -hydroxy-1'-thiophene) naphthene used in this example may be made as follows:-

By the action of phosphorus pentachloride on 8-bromo-naphthalene:l-sulfonic' acid, the 8- bromo-naphthalene-l-sulfochloride is obtained; 7 it crystallizes from benzine'in lustrous laminae 1. Unsymmetrical indigoid dyestufis of the gen eral formula s halogen which dyestuffs are dark brown powders yielding in cotton printing blackish-brown tints of excellent fastness properties.

p Q,09c,i4o of melting point 102-103 C. By reduction with 2. The unsymmetrical indigoid dyestufi of the formula 01 S\ /CO which dyestufi is a. dark brown powder yielding in cotton printing blackish brown tints of excelv lent fastness properties.

3. The unsymmetrical indigoid dyestufi of the,

formula which dyestuff is a dark brown powder yielding in cotton printing blackish brown tints of excellent fastness properties. W

ROBERT S TOCKER. JAKQB 

